1. Field of the Invention
This invention relates to heat retention within torpedo cars, and more specifically toward improvements in insulating covers which are configured for easy and safe positioning on torpedo cars.
2. Description of the Prior Art
Torpedo cars, also referred to as ladle cars, are employed for carrying molten metal from one location to another. Typically, the hot metal is transported between the blast furnace and the melt facility by a torpedo car. It is desirable to retain the temperature within the torpedo car as high as possible between the emptying of and the subsequent refilling with molten metal. Temperature retention is desired to minimize the molten metal temperature loss occurring during the next refilling.
It is well known to form a shield or insulating cover to cover the opening of a torpedo car, such as a wire mesh enclosed refractory containing sheet. Examples of such insulating covers can be found in U.S. Pat. Nos. 4,381,855; 4,390,170; 4,424,956; and 4,424,957. These prior art insulating covers have several disadvantages including difficulty in manually engaging and positioning these covers on the torpedo car opening with hooks or the like.
A more recent invention disclosed in U.S. Pat. No. 5,882,576 was developed to overcome the drawbacks of the aforementioned prior art insulating covers. That invention teaches an insulating cover for covering an opening in a torpedo car. The insulating cover includes an upper wire mesh layer and a lower wire mesh layer with an insulating layer positioned between the upper and lower wire mesh layers. Tie devices secure the upper wire mesh layer and the lower wire mesh layer together and hold the insulating layer in position. Additionally, a pair of ferromagnetic plates are coupled to the upper wire mesh layer, whereby each ferromagnetic plate provides a lift point for lifting the insulating cover, such as with an electromagnet or the like.
In that invention, a pair of support rods may be positioned with one of the support rods between each ferromagnetic plate and the lower wire mesh layer. Each support rod extends beyond the side edges of the upper and lower wire mesh layers and has a length greater than the width of the torpedo car opening.
In one embodiment, each ferromagnetic plate is positioned on top of the upper wire mesh layer and includes a pair of support strips extending below the upper wire mesh layer and forming a locating hole on the underside of the ferromagnetic plate. A support rod extends through the locating hole to couple the ferromagnetic plate to the upper wire mesh layer. Tie devices secure each support rod into position.
That insulating cover may be shaped to fit within the opening of the torpedo car such that the upper and lower wire mesh layers each include a pair of planar outer sections and a recessed central section. This formed configuration with the recessed central section will provide a better fit of the insulating cover within the opening of the torpedo car.
That insulating cover is easily manufactured according to the following steps. The lower wire mesh layer, the upper wire mesh layer, and the insulating layer positioned between the upper and lower wire mesh layers are positioned on a bending frame. The upper and lower wire mesh layers are bent on the bending frame to form the pair of planar outer sections and the recessed central section. The ferromagnetic plates are appropriately coupled to the upper wire mesh layer. The upper and lower wire mesh layers are secured together with the tie devices, thereby maintaining the insulating cover together.
However, sometimes the support rods in the torpedo car cover of U.S. Pat. No. 5,882,576 interfere with the forklifts used to transport the cover to and from the area of the torpedo car since the support rods extend beyond the side edges of the wire mesh layers. When a forklift approaches the cover, the support rods deflect the cover and make it difficult to maneuver the forklift to pick up the cover.
Therefore, a need exists to develop a torpedo car cover that is easily manufactured, installed, and removed.
The present invention provides improvements to an insulating cover for covering an opening in a torpedo car. The insulating cover of the present invention includes an upper wire mesh layer and a lower wire mesh layer with an insulating layer positioned between the upper and lower wire mesh layers. The insulating layer may extend beyond the peripheral edges of the upper and lower wire mesh layers and may be formed of a ceramic fiber material.
Tie devices secure the upper wire mesh layer and the lower wire mesh layer together and hold the insulating layer in position. The tie devices may include a plurality of wire ties extending through the insulating layer and securing the upper and lower wire mesh layers together.
A pair of ferromagnetic plates is coupled to the upper wire mesh layer, whereby each ferromagnetic plate provides a lift point for lifting the insulating cover, such as with an electromagnet or the like. One embodiment of the present invention provides that the upper and lower wire mesh layers be substantially formed of 6xe2x80x3xc3x976xe2x80x3 wire grid with each of the ferromagnetic plates being a 6xe2x80x3xc3x9712xe2x80x3 steel plate.
The insulating cover may be shaped to fit within the opening of the torpedo car such that the upper and lower wire mesh layers each include a pair of planar outer sections and a recessed central section. This formed configuration having the recessed central section will provide a better fit for the insulating cover within the opening of the torpedo car.
In one embodiment, a support rod may be positioned between the upper and lower wire mesh layers to extend beyond the ends of the upper and lower wire mesh layers. The support rod has a length greater than the widest portion of the torpedo car opening. Each of the pair of ferromagnetic plates is positioned on top of the upper wire mesh layer and includes at least one support strip extending below the upper wire mesh layer and forming a locating hole on the underside of the ferromagnetic plate. The support rod extends through the locating hole to couple the ferromagnetic plate to the upper wire mesh layer. Tie devices secure the support rod into position.
In another embodiment, a pair of support rods may be positioned forming an xe2x80x9cXxe2x80x9d over a central portion of the insulating cover. The pair of support rods is positioned between the upper and lower wire mesh layers to extend beyond the side edges of the upper and lower wire mesh layers. Each support rod has a length greater than the widest portion of the torpedo car opening. Tie devices secure the support rods into position.
Either end of the support rod or rods may be straight or turned on itself to form a blunted or rounded end. This avoids the unsafe condition of a rather pointed rod end spearing someone or something.